Roblox 4D Objects, Speech API & Custom Matchmaking

Beyond The Blox

12 November 2025

Adam Whitney

Adam and Fedor looking at some 4D-generated Roblox cars, shown as part of Roblox's marketing.

We had a packed episode this week, covering everything from magical object generation to granular control over who plays together in your servers.

4D Generation: The "Magic" of User-Created Objects

Roblox is calling it "4D Generation," and while the name might be a bit of marketing flair, the technology is genuinely impressive. Shown off at RDC with a "watermelon shooting banana gun," this Early Access feature allows users to describe an object in real-time, which is then generated based on developer-defined controls.

The core idea is a partnership between the developer and the user. The developer defines the schemas and behavior—for example, a car must have four wheels, a body, and a steering wheel—and the user provides the creative spark, like "make it a rainbow cat car." The engine then generates the geometry and textures to fit those constraints.

We discussed the implications for monetization. In a world where players can generate the exact "shiny" item they want, the traditional model of selling cosmetic skins might need to evolve. Developers may need to shift focus towards monetizing custom behaviors or access to these generation tools themselves. There are also significant questions around IP; however, Roblox seems to be taking a cautious approach, routing prompts through safety and IP filters to prevent unauthorized generation of licensed content like branded cars.

Speech-to-Text: Casting Spells with Your Voice

The new Speech-to-Text API (Beta) opens up fascinating gameplay possibilities. Instead of just using voice for chat, developers can now process spoken words into text to trigger game actions. The immediate use cases are obvious but powerful: casting spells by reading them aloud, issuing voice commands to units, or even conversing with AI-driven NPCs.

There are some current limitations to be aware of. It is not a continuous transcription service; you get about 10 seconds of audio per request, and there are rate limits based on concurrent users. This means it is best suited for discrete interactions—like a "push-to-talk" command system—rather than full-time accessibility subtitles.

In-Experience Creation: The Next Evolution of UGC?

We are seeing the early steps of "In-Experience Creation" for accessories and layered clothing. This Client Beta allows players to customize specific items within a game—think painting a t-shirt or modifying a jacket using tools provided by the developer—and then purchase that unique item to wear across Roblox.

Fedor pointed out the potential for players to build their own UGC businesses entirely within another game, bypassing the need for external tools like Blender. However, items created this way are currently unique to the creator and cannot be traded or sold to others, though that could change. One sticky point is moderation: if you pay to create an item and it gets rejected by moderation, there is currently no automatic refund, which could be a friction point for younger creators.

More Server CPU & Dynamic Allocation

For the infrastructure nerds (like me), the rollout of dynamic server CPU allocation is a huge win. Previously, server resources were somewhat static based on maximum player counts. Now, Roblox is increasing the baseline CPU for everyone and dynamically scaling resources based on the actual number of players in the server at any given time.

This is a "magic switch" update—developers do not need to do anything, and their games just run better. It is particularly beneficial for CPU-intensive games using large maps and streaming, ensuring that as player counts rise, the server can keep up with the demand.

Configs and Experiments: No More Blind Darts

Fedor used a great analogy in this episode: developing without analytics is like throwing darts at a dartboard with your eyes closed and waiting to hear the crowd's reaction. The new Configs and Experiments (A/B Testing) features turn the lights on.

Developers can now roll out changes to a subset of players—say, giving 10% of users a different boss health value or a new store layout—and compare the analytics against the control group. If retention or monetization drops, you can kill the experiment without crashing the whole game. If it goes up, you can roll it out to everyone. This brings a level of professional live-ops to Roblox that was previously very difficult to achieve manually.

Custom Server Matchmaking

Finally, we discussed the rollout of Custom Server Matchmaking to all experiences. This gives developers granular control over how players are grouped into servers. You can now assign weights to existing signals like:

Latency: Critical for competitive shooters.
Language: Vital for social or roleplay games.
Age: Useful for keeping peer groups together.
Device Type: Separating mobile and PC players for balance.

Even better, you can add custom signals. If your game has a skill rating or an XP level, you can pass that into the matchmaking logic to ensure noobs are not getting stomped by veterans, which vastly improves the new user experience.

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